Mass spectrometry will be employed in the study of a number of biomedically important problems. Structures of antibiotics belonging to the polyene (hamycin, aureofungins, vacidin, candimycin) and oligopeptide (emerimicin, zervamicin) classes of antibiotics will be investigated, as will structures of scopafungin and an antiviral substance from streptovaricin complex. Extracts of marine species (especially sponges and algae) will be studied for antibacterial, antifungal, antitumor and antiviral activities. To carry out these studies we plan to stress high resolution field desorption as well as electronic impact and field ionization gas chromatographic mass spectrometric techniques (HRFDMS, HREIGCMS, HRFIGCMS). We also plan to use capillary glass columns and, perhaps, a californium radiation ion source.